The treatment of many serious medical conditions is almost exclusively performed systemically. However, there are certain medical conditions for which non-systemic (including topical) treatment may be more suitable, such as conditions including, but not limited to, those affecting the skin, the gastrointestinal (GI) tract (including the oropharynx), the eye, ear, nasopharynx, bladder, vagina and cervix.
Skin cancers account for around 81% of all new cancers diagnosed each year in Australia. There are three main types of skin cancer: basal cell carcinoma and squamous cell carcinoma (also known as non-melanoma skin cancers) and melanoma. Non-melanoma skin cancer is the most frequently occurring cancer in Australia (over 374,000 new cases each year), but the least life-threatening, although some cases can be fatal.
GI cancers include a large variety of cancers including colorectal cancers. Globally, colorectal cancer (cancer of the large bowel) is the third most common cancer in men and women, representing 13% of all cancers. In Australia, it is the second most common cancer in both men and women. About 20 percent of patients have metastatic disease (spreading beyond the large bowel) at the time of diagnosis, and 50 percent of all colorectal cancer patients will develop metastases and ultimately die from their disease. About 56,000 people die from colorectal cancer every year in the US and the mortality rate in Europe exceeds 100,000 patients per year.
Colorectal cancers are solid tumours (growths) which start in the innermost layer (that is the endothelial lining) of the intestine and can grow through some or all of the other layers. Colon cancers arise from benign neoplasms and evolve into adenocarcinomas through a stepwise histological progression sequence, proceeding from either adenomas or hyperplastic polyps/serrated adenomas.
Colorectal cancer usually begins with the growth of polyps. In 1994, more than 2,000,000 colonoscopies were performed in the US and over 650,000 of these patients underwent polypectomy. Early detection and removal of polyps significantly reduces the incidence of colorectal cancer. However, about 50 percent of people aged 60 will have at least one adenomatous (potentially cancerous) polyp of 1 cm diameter or greater.
Since a large proportion of patients presenting with colorectal cancer present at a late stage in the disease it would be desirable to have a treatment which could aid in the prevention and/or treatment of colorectal cancer without the need for surgery, or to reduce the risk of recurrence after surgery, for instance after a polpectomy.
Oesophageal cancer is now the ninth most common cancer in adults in the UK. A precursor condition of oesophageal cancer is Barrett's oesophagus. In Barrett's oesophagus, the cells lining the oesophagus change to resemble the cells lining the stomach. It may develop following long-term acid reflux from the stomach. People with Barrett's oesophagus are 125 times more likely to develop oesophageal cancer than the average person.
Head and neck cancer, including oral and pharyngeal cancer, is the sixth most common malignancy reported worldwide and has very high mortality ratios for all malignancy types. About 90 percent of head and neck cancers are of the squamous cell variety. Although there have been significant improvements in chemotherapy and surgical techniques, the disease is often particularly challenging to treat since most patients present with advanced disease, have secondary tumours and suffer from other co-morbidities.
Bladder cancer is the fourth most common cancer in men, with more than 10,000 people diagnosed with the disease each year in the UK. Bladder cancer is rare in people under 40; the average age at diagnosis is 65. By the time of diagnosis, about 85% of bladder cancers are still limited to the bladder. Bladder cancer usually starts in the mucosa and, for a while, only grows towards the inside of the bladder.
Cancers of the eye are not common, but are a serious set of conditions which require effective methods of treatment and prevention. Cancers can occur in all parts of the eye. The most common malignant primary intraocular tumor in adults is melanoma. Though most attention is given to posterior choroidal melanoma, these tumors can also occur in the iris and ciliary body. The most common eyelid cancer is basal cell carcinoma. This cancer can grow around the eye but rarely spreads to other parts of the body. Other types of common eyelid cancers include squamous carcinoma, sebaceous carcinoma and malignant melanoma.
Uterine cancer is the most common gynaecological cancer. Most cancers of the uterus are cancers of the lining of the uterus (the endometrium). Cancers can also develop in the muscle layers of the uterus. Other, less common, types of cancer of the uterus are adenosquamous carcinoma, papillary serous carcinoma and, rarely, clear cell carcinoma or uterine sarcoma. These cancers are aggressive and are more likely to metastasise. Cervical cancer, although less common than uterine cancer, typically begins in the squamous cells that cover the outer surface of the cervix.
It would be desirable to have a treatment which could aid in the prevention and/or treatment of the above, and related, conditions without the need for surgery, or to reduce the risk of recurrence after surgery.
The discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.